The effect of pressure on the opening of devices which relieve pressure is broadly known in the prior art, inasmuch as there are a multiplicity of fast opening devices which, upon detecting an increase in the pressure beyond a predetermined limit, which may even be dangerous, open or break in this emergency instances due to the direct effect of the pressure change. Examples of these devices at the industrial level are the safety or relief valves or the rupture discs which are included as safety devices in containers working at high pressures, or at the domestic level the safety valves which are used in pressure kettles and the like.
On the other hand, there is also a large variety of receptacles divided into various compartments which, on opening by means of some external agent, permit the admixing of substances within the receptacle, as is the case of the light sources by chemical reaction which are used in dividing, in which, in order to accomplish the opening of a receptacle which is contained within another receptacle, stresses are applied on the outer flexible surfaces of the walls of the outer receptacle, with which said walls apply a corresponding stress on the outer rigid surface of the wall of the inner receptacle, breaking the same and producing a crack in said wall of the inner receptacle for accomplishing the admixing of the contents of the two receptacles.
There is on the other hand a constant need of admixing products for consumption thereof, such as medicines, food products, reactants, and the like, but in many of these cases, when the mixing of the substances is effected, such as for instance, the admixing of a solute with a solvent, the mixtures are quickly degraded by a plurality of chemical or biological reactions, which considerably shorten the useful life of the solution, whereby at present it is preferred to keep said products (solid and solvent) stored in separate containers to be admixed at the precise time of use. If on the contrary said substances are packaged within a container after admixing the same, it is usually necessary to give to the resulting solution a special treatment such as sterilization or the addition of radioactive isotopes in the case of milk, for instance, or the addition of preservers in the case of food products, or the addition of pH regulators or buffers in the case of reactants.
The need of a practical fast opening system is critical, for instance, in nursing bottles for feeding babies, in which the normal procedure known in the prior art is to admix the powdered milk with water within the nursing bottle. However, between the moment of preparing the milk and the ingestion thereof a long period of time may pass, in which bacterial colonies may be developed, thus increasing the possibility of causing a gastrointestinal infection to the baby consuming said mixture. It is for this reason that, when the milk is not to be consumed immediately, it becomes necessary to carry the powdered milk and the water in separate containers, and to admix both substances at the precise time of consumption by the baby, which practice shows the important drawback that there is the possibility of introducing contaminant particles within the nursing bottle, originating from the environment or from the natural manipulation which is effected for admixing both substances.
The nursing bottles known in the prior art, on the other hand, have the drawback that the longitudinal axis of the nursing bottle has to be located in a neutral position or with a negative slope, in order for the milk to come out through the sucker device, thus forcing the baby to adopt a position in which his head in a nearly horizontal direction, and to constantly hold the nursing bottle in the above said position in order to ingest the liquid, this increasing the incidence of middle ear infections and bronchial inhaling, because of the position that the Eustaquio tubes and the epiglottis respectively adopt.
U.S. Pat. No. 4,676,387 patented to Jim D. Stephenson on Jun. 30, 1987, describes and claims a nursing bottle comprising a body having a lower cylindrical section and an upper cylindrical section of the same diameter, the body of the bottle having a configuration including an angle between both above cylindrical sections, which is spaced from the top end of the bottle in an intermediate position between the top end and the bottom end thereof. Regardless of the fact that said nursing bottle solves the problems caused by the position that the baby is forced to adopt with all other prior art nursing bottles which are formed with a single cylindrical body, it nevertheless presents the same problems as conventional nursing bottles, inasmuch as it is necessary to mix the solute and the solvent previously or to handle said solute and solvent in a separate manner until shortly before the time of use.
In view of the above, it may be concluded that none of the prior art nursing bottles has fulfilled the purpose of providing and efficient nursing bottle which will avoid the inconvenience of having to handle the solute and the solvent in a separate manner till the moment of use, or of generating strong bacterial proliferation when the mixture is prepared previously, with the consequent increase in the possibility of causing a gastrointestinal infection to the baby consuming said mixture.